The rate of glucose metabolism by a living cell is known to be a useful indicator of a variety of abnormal physiological conditions, particularly in human patients. Included among these conditions are various forms of cancer, coronary artery disease, brain tumors and epilepsy. The diagnosis and locale determination of these conditions has been made possible by sophisticated imaging techniques that identify cells which are demonstrating abnormally high or low rates of glucose intake.
Imaging up until now has been performed by positron-emission tomography (PET) with glucose analogs such as carbon-11-labeled glucose and .sup.18 F-labeled 2-deoxy-2-fluoro- D-glucose and its isomer .sup.18 F-labeled 3-deoxy-3-fluoro-D-glucose (the last two are referred to as "2-FDG" and "3-FDG," respectively). The analogs, upon administration to the patient prior to the imaging procedure, enter the cell in the same manner as glucose, and the resulting whole body distribution of the analogs as detected by the imaging procedure indicates the stage and locus of the abnormality. These are the only known analogs which will achieve transport across the cell membrane in the same manner as glucose, because derivatization of the glucose molecule destroys the receptor specificity of the molecule, thereby interfering with its transport. PET is the imaging technique of choice because it is sensitive enough to usefully detect the annihilation photons emitted by these analogs. The advantage of the FDG's over carbon-11-labeled glucose is that, unlike the carbon-11-labeled glucose, the FDG's do not complete the metabolic cycle inside the cells, and therefore remain in the cells long enough for imaging to take place.
Unfortunately, PET is one of the more costly imaging procedures. As a result, nuclear medicine scanning based on glucose transport abnormalities has enjoyed only limited use, and is feasible only at locations where PET equipment is available. This has hindered the development of glucose transport both as a research tool and as a diagnostic method.